Data Types

One of the most fundamental characteristics of a programming language is the set of data types it supports. These are the type of values that can be represented and manipulated in a programming language.

The Dart language supports the following types−

• Numbers
• Strings
• Booleans
• Lists
• Maps

Numbers

Numbers in Dart are used to represent numeric literals. The Number Dart come in two flavours −

• Integer − Integer values represent non-fractional values, i.e., numeric values without a decimal point. For example, the value “10” is an integer. Integer literals are represented using the int keyword.
• Double − Dart also supports fractional numeric values i.e. values with decimal points. The Double data type in Dart represents a 64-bit (double-precision) floating-point number. For example, the value “10.10”. The keyword double is used to represent floating point literals.

Strings

Strings represent a sequence of characters. For instance, if you were to store some data like name, address etc. the string data type should be used. A Dart string is a sequence of UTF-16 code units. Runes are used to represent a sequence of UTF-32 code units.

The keyword String is used to represent string literals. String values are embedded in either single or double quotes.

Boolean

The Boolean data type represents Boolean values true and false. Dart uses the bool keyword to represent a Boolean value.

List and Map

The data types list and map are used to represent a collection of objects. A List is an ordered group of objects. The List data type in Dart is synonymous to the concept of an array in other programming languages. The Map data type represents a set of values as key-value pairs. The dart: core library enables creation and manipulation of these collections through the predefined List and Map classes respectively.

The Dynamic Type

Dart is an optionally typed language. If the type of a variable is not explicitly specified, the variable’s type is dynamic. The dynamic keyword can also be used as a type annotation explicitly.